Physicochemical-activity relations in practice. 1. Rational and self-consistent data bank

Abstract

A data bank of substituent constants of 26 ortho and 34 meta and para benzenoid substituents is presented for use in physicochemical-activity relations (PAR) studies. The distributive parameters pri and pri-, a bulk parameter based on molar refraction, and positionally weighted electronic parameters F and R are listed for the three substituent positions. There are no gaps in the table caused by missing values and the interparameter correlation are low.

Determination of Octanol/Water Partition Coefficients for Hydrophobic Organic Chemicals With the “Slow-Stirring” Method

“…The rather low value of the correction factor for the chlorobenzenes is probably the result of the reduction of KO, values for para-substituted congeners. The ?r constants for meta and para chlorine atoms in chloroanilines are in fair agreement with the a-constants that were reported by Norrington et al [31]. However, the a constant for ortho substitution is, as expected, considerably higher than the ?r-value that Norrington reported (0.69).…”

Cytotoxicity and topoisomerase I/II inhibition activity of novel 4-aryl/alkyl-1-(piperidin-4-yl)-carbonylthiosemicarbazides and 4-benzoylthiosemicarbazides

“…In order to clarify the effect of steric and electronic properties of substituents on cytotoxic potency of tested 4-arylthiosemicarbazides (4-6), some parameters such as the bulk parameter based on molar refraction MR and the positionally weighted electronic parameters F and R were taken from the literature 22 and correlated with biological activity. Experiments have shown 23,24 that a parameter representing the volume of the substituents on each compound, relative to other members of the same series, may often be linearly correlated with the biological response.…”

Pyrazinecarboxylic Acid Derivatives with Antimycobacterial Activity

“…8 and in Tables 1 and 3). Their chemical structure, electronic parameters expressed as Hammett's σ parameter (Norrington et al, 1975), hydrophobic parameters (experimentally determined log k, experimentally determined distributive parameters π Ph for individual aniline substituents, log P calculated by ACD/LogP DB), solubility (log S calculated by ACD/LogS DB), dissociation constants (pK a calculated by ACD/pK a DB), antituberculotic inhibiting activity and structure-activity relationships (SAR) were studied. The following was synthesized in preference: (i) compounds with lipophilic and/or electron-withdrawing substituents on the benzene moiety (R 3 ), (ii) compounds with hydrophilic and/or electron-donating groups on the benzene part of the molecule (R 3 ), and finally (iii) compounds with a lipophilic alkyl chain (R 2 ), i.e.…”

“…Electronic parameters are expressed as Hammett's σ parameter (Ref. Norrington et al, 1975). Compounds are ordered according to their decreasing inhibiting activity (Ref.…”